dovecot: replace solr fts with flatcurve (xapian) (#5680)

* fts-flatcurve: inital implementation

* fts: removed solr from compose.yml

* flatcurve: added heap and proc logic to dovecot

* added logic for update.sh & generate for Flatcurve

* delete old iteration of fts-flatcurve.conf

* updated default fts.conf

* updated .gitignore to exclude fts.conf for further git updates

* Remove autogeneration of fts.conf (disable override)

* cleanup all left solr stuff

* renamed SKIP_FLATCURVE to SKIP_FTS

* cleanup leftovers solr in lang files

* moved lazy_expunge plugin only to mail_plugins

* added fts timeout value

* compose: remove dev image of dovecot

* updated japanese translation

data/Dockerfiles/dovecot/Dockerfile

@@ -105,7 +105,6 @@ RUN addgroup -g 5000 vmail \
   dovecot-submissiond \
   dovecot-pigeonhole-plugin \
   dovecot-pop3d \
-  dovecot-fts-solr \
   dovecot-fts-flatcurve \
   && arch=$(arch | sed s/aarch64/arm64/ | sed s/x86_64/amd64/) \
   && wget -O /usr/local/bin/gosu "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$arch" \